Supporters of presidential candidate Andrés Manuel López Obrador gather after his victory in the presidential election in Mexico City on July 1. (Goran Tomasevic/Reuters)

ByMagda Hinojosaand

Jennifer M. Piscopo

July 11

While observers discuss leftist Andrés Manuel López Obrador’s victory in Mexico’s presidential election, complete with majorities in both chambers of congress and control of nearly half the governorships and state legislatures up for election, another historic earthquake has been overlooked: gender parity in congress.

When the new Mexican congress sits on Dec. 1, women will make up 49 percent of the lower house and 51 percent of the senate. Mexico will rank fourth in the world for women’s legislative representation. And it will be the only country with an elected senate that is majority female.

Across the board, Mexican women won big in the July 1 elections. The second most important political position in the country (mayor of Mexico City) also went to a woman. At the subnational level, women will make up 50 percent of most state legislatures.

But the forces bringing AMLO — as López Obrador is widely known — and women into office are different. AMLO’s election speaks to Mexicans’ desire for change. Women’s wins are the result of 15 years of electoral reforms, in which Mexico incrementally refined the affirmative action rules that compel political parties to nominate women.

How did Mexico do it? And will women help AMLO transform Mexico?

Gender quotas for legislatures are a global trend

More than 75 countries have some form of gender quota for the legislature. Most commonly, gender quotas are imposed via candidate quotas — requirements that political parties nominate certain percentages of women. All Latin American countries except Guatemala and Venezuela have such laws.

Gender quotas work because parties control access to the ballot. Unlike in the United States, candidates in most parts of the world cannot simply run on their own initiative. Rather, parties select and register their candidates. Quota laws essentially regulate parties’ candidate selection processes.

Not all gender quotas work equally well. Brazil has a 30 percent candidate quota for women, but fewer than 15 percent of those actually elected are women. It is tempting to blame voters because Brazil has a system in which voters pick their preferred candidates off the party’s electoral slate. But as research shows, the real problem is that parties run women in losing districts, give women fewer resources for their campaigns and generally fail to support female candidates.

Mexico, by contrast, imposed strict rules on how parties could fill the quota.

But these maneuvers resulted in huge scandals. By 2009, prominent female politicians from the left and right pushed back, forming a cross-party coalition and pressing officials of the National Electoral Institute to rewrite the quota rules.

They also took the parties to court. In 2011, women won a landmark case requiring parties to respect the quota at all costs. The court struck down both the primary exemption and parties’ ability to pair candidates with alternates of the other sex.

In 2014, Mexico amended its constitution to require gender parity for candidacies for the federal and state legislatures. The new electoral code stipulated that parties could not send female candidates exclusively to losing districts. And so we come to 2018’s results.

Before Mexico’s mandatory 30 percent quota, women held just 17 percent of seats in the lower house — a proportion not far from the 20 percent of seats women hold today in the U.S. House of Representatives. Now Mexico leaves the United States — and most of Latin America — far behind on women’s representation.

Second, quotas can work in districts represented by single members. Mexico elects its lower house via a mixed system, with 300 seats allocated in single-member districts. Parity requires that parties nominate women to 150 districts. The National Electoral Institute looks for parity not just across districts, but across district type: Are nominations distributed 50-50 across winning, swing and losing districts?

Third, neither party ideology nor parties’ goodwill explains when parties nominate women. Our research shows no variation across left and right parties in nominating women, no matter the quota rules in place.

Mexico illustrates all this. In 2015, parties on the left and right fell short of parity by district type. Parties nominated women and men to winning districts at a ratio of 45 percent to 55 percent — but to losing districts at a ratio of 54 percent to 46 percent. The National Electoral Institute publicized these differences. Chastised, the parties did better in 2018, and women won 30 more single-member districts.

AMLO also announced a gender parity cabinet, with women in top posts: energy, labor and social welfare, and the economy. He has picked a woman to be minister of government — the most influential position in the administration.